Posted by: Ger Rietman | September 17, 2016

NemaStudio now supports the NMEA 0183 TAG Block



From version 1.32 NemaStudio supports the TAG block as defined in NMEA 0183 Version 4.0.

NMEA’s definition of the TAG Block

The NMEA defines the function of the TAG Block as follows:

“The TAG Block structure and content is intended to clarify the relationship of sentences to each other and to the equipment between which sentences are communicated. The TAG Block structure introduces the addition of sentence related information into the character stream containing NMEA 0183 defined sentences.”

The TAG Block format

Basically a TAG Block contains one or more parameters. A parameter has a parameter code and a parameter value. Parameter example: “-s:GP0003”. Currently a maximum of 7 different parameters are defined (See below).

A TAG Block always starts and ends with a backslash (“\”” and includes a checksum preceded by an asterisk (“*”).   The TAG Block always precedes the NMEA 0183 sentence. Example TAG Block (red) preceding HDT sentence:


TAG Block parameters

Currently the TAG Block can contain one or more of the following parameters:

Parameter code Parameter name NemaStudio support
-c UNIX time yes
-d Destination Id no
-g Grouping no
-n Line count yes
-r Relative time no
-s Source Id yes
-t Text string no


As can be seen from the table NemaStudio V.1.32 supports   the following TAG Block parameters: –c, –n and –s. Depending demand Sailsoft may include more parameters in future versions of NemaStudio.

The TAG Block is optional

Using the TAG Block is optional and can be set in the NMEA settings tab of the General Settings. This ensures compatibility with applications that do not support the TAG Block. The TAG Block and the parameters can be selected individually in NemaStudio. If the checkbox “Send TAG Block” is unchecked the parameter checkboxes are disabled.

Examples with TAG Block and Multicast UDP from NemaStudio


(Note: the question mark after the UdPbC string represents the null terminator.)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s


%d bloggers like this: